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 A051730 Distance from A051650(n) to nearest prime. 18
 2, 4, 6, 7, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 24, 25, 26, 30, 31, 32, 33, 34, 35, 36, 40, 42, 43, 44, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 96, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 LINKS Amiram Eldar, Table of n, a(n) for n = 0..211 (calculated from the b-file at A051650) EXAMPLE 23 is 4 units away from the closest prime (not including itself), so 4 is in the sequence. MATHEMATICA (* b stands for A051650 *) d[0] = 2; d[k_] := Min[k - NextPrime[k, -1], NextPrime[k] - k]; b[0] = 0; b[n_] := b[n] = (k = b[n-1] + 1; record = d[b[n-1]]; While[d[k] <= record, k++]; k); a[n_] := a[n] = d[b[n]]; Table[ Print[ a[n]]; a[n], {n, 0, 66}] (* Jean-François Alcover, Jan 16 2012 *) PROG (UBASIC) [10] C#=pack(3, 5):R=2:N=4:print 2; [20] if N>member(C#, 2) then C#=pack(member( C#, 2)):C#=C#+nxtprm(member(C#, 1)) [30] Prv=member(C#, 1):Nxt=member(C#, 2) [40] if Nxt=N then Nxt=nxtprm(N) [50] if (N-Prv)>=(Nxt-N) then P=Nxt-N else P=N-Prv [60] if P>R then print P; :R=P [70] N+=1 :goto 20 (PARI) print1(w=2); p=2; q=3; forprime(r=5, 1e9, if(p+w+ww, w=t; print1(", "t)); p=q; q=r) \\ Charles R Greathouse IV, Jan 16 2012 CROSSREFS Related sequences: A023186-A023188, A046929-A046931, A051650, A051652, A051697-A051702, A051728-A051730. Sequence in context: A070125 A263084 A029501 * A070317 A138398 A086781 Adjacent sequences:  A051727 A051728 A051729 * A051731 A051732 A051733 KEYWORD nonn,easy,nice AUTHOR EXTENSIONS More terms from James A. Sellers, Dec 23 1999 and from Jud McCranie, Jun 16 2000 Further terms from Naohiro Nomoto, Jun 21 2001 STATUS approved

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Last modified August 20 22:45 EDT 2019. Contains 326155 sequences. (Running on oeis4.)